Systems and methods for sensing and/or imaging samples can rely on a number of different techniques including relying on a probe light beam to interrogate the sample. Beams of different wavelengths interact differently with different samples. As a result, for a given sensing technique that relies on a given interaction between the probe beam and the sample, the appropriate wavelength should be chosen to produce the given interaction. For example, if a sensing technique relies on measuring the portion of the probe light beam that is transmitted through the sample, then the wavelength of the probe light beam can be chosen such that the sample at least partially transmits the probe light beam.
Moreover, different wavelengths can interact with different features and/or portions of the sample and yield different sensing information. In addition, in some applications the probe light beam can be chosen to be non-destructive to the sample. As such, a large variety of sensing techniques are needed to provide adequate sensing options for sensing the various properties of different types of samples.
In addition to using an optical probe beam, acoustic waves can also be used to sense a sample. However, acoustic waves can require a coupling medium disposed between the sample and the sensor, to allow for adequate transmission of acoustic waves between the sample and the sensor. These coupling mediums are often liquids. However, some samples need to be maintained in a dry state and cannot be used in conjunction with a liquid coupling medium.